The present invention relates to a disk array device in which a plurality of disk drives are mounted, and an electronic device having a heating element such as a CPU.
A disk array device has several magnetic or optical disk drives which are mounted in a housing in order to enhance the reliability of data storage. These disk array devices are connected to a high speed dedicated network line which is optical or the like, and are operated under a management software. In this operation, these devices are used in an SAN (storage area network), an NAS (network attached storage) or a single RAID (Redundant Array of Inexpensive Disks). A disk drive mounted in each of these disk array devices has a drive motor, an actuator and electronic control components including an LSI, which are main heat sources therein. The heat sources are cooled by cooling air fed from a cooling fan incorporated in the housing of the disk array device.
In the case of having a low cooling capacity, the temperature of the disk drive increases, and as a result, there would be possibly caused a risk of erroneous operation and lowering of the long period reliability. Further, a controller managing the transmission of data between external control equipments and disk drives generates a highly capacitive heat. Thus, in the case of such a low cooling capacity, the temperatures of the controller and the like are increased, resulting in erroneous operation and damages to electronic components.
Further, there would be an important task for reducing noises produced from a fan for driving an air flow within the disk array device since no sufficient air volume for the cooling would not be ensured due to a noise problem. Thus, the disk array devices inherently have raised both tasks of satisfactorily cooling electronic components such as a CPU which generate a heat and lowering noises in the device. Electronic devices having a heat source such as a CPU, have also raised similar tasks.
In the most of conventional disk array devices and electronic devices, a fan is incorporated within a housing in order to lower noises. In this case, the fan possibly transmits vibration to a disk drive in view of its structure. Should the peak vibration frequency of the fan be coincident with a natural frequency of the disk drive, there would be caused a risk of impeding the reading and writing of the disk drive.
The disk array device and the electronic device are usually used with their doors being closed. However, the doors would be opened during service and maintenance thereof, such as replacement of disk drives. In order to carry out the maintenance for the disk arrays device or the electronic device without stopping the operation thereof, it is important to maintain the cooling capacity for components accommodated in a housing and being apt to be heat source even in such a case.
Abrupt increase in power consumption has become critical problems to be solved under the management of a data center due to spread using of blade servers and increasing of a scale of storages. For example, the heating value of a server has been increased by 20 to 25% on an annual base, and it is prospected that the power of about 20 kW per unit will be consumed after a lapse of several years. That is, it is considered that the ratio between power consumption by a server and power consumption for cooling the server will be increased from 1:1 to 1:1.5 to 2.0. Accordingly, the power consumption required for the cooling has become a critical problem.
In the case of arranging several disk array devices and electronic devices in one and the same space as in the conventional data center or the like, there has been generally used an air-conditioner with the configuration that cooling air is fed from a portion underneath the floor of a building and heated air is exhausted from the ceiling of the building. In the case of mounting disk array devices and electronic devices in a densely packed condition, there would be cased the problem that heated air around the ceiling is likely to be again reintroduced in the disk array devices, mainly causing an increase in the costs of air condition, and a limitation to the number of equipments to be mounted.
As a conventional data center, JP-A-2006-208000 discloses a system for monitoring an air stream so as to enhance the cooling efficiency, and controlling the cooling in the data center in dependence upon a detected air stream. Further, JP-A-2007-505285 discloses a system for determining an index value of recirculation of air stream.
In conventional electronic equipment, louvers are formed in an equipment housing in order to uniformly cooling the equipment in the housing as disclosed in JP-A-2000-49482 and JP-A-11-204974.
The conventional technology as disclosed in JP-A-2006-208000 and JP-A-2007-505285 requires sensors provided in several parts in the data center and a controller for determining a situation, and accordingly, has a complicated configuration. Further, no process for enhancing the cooling efficiency of the device itself is disclosed.
The technology as disclosed by JP-A-2000-49482 and JP-A-11-204974, focuses only to pneumatic control in the housing, that is, it does not concern control of intake and exhaust air.
Further, JP-A-2006-208000, JP-A-2007-505285, JP-A-2000-49482 and JP-A-11-204974 do never disclose the technology of lowering noises generated from the disk array device and an electronic device.